var evalRPN = function(tokens) {
    const res = [];
   for(let i = 0; i < tokens.length; i++) {
       let ch = tokens[i];
       if(ch!='+' && ch!='-' && ch!='*' && ch!='/') {
           res.push(ch)
       }
       switch (ch) {
            case '+' : res.push(Number(res.pop()) + Number(res.pop()));
            break;
            case '-' : res.push(-res.pop() + res.pop());
            break;
            case '*' : res.push(res.pop()*res.pop())
            break;
            case '/' : res.push(Math.trunc(1/(res.pop()/res.pop())));
           
            break;
       }
   }
   return res[0];
};
console.log(evalRPN(["10","6","9","3","+","-11","*","/","*","17","+","5","+"]))
let a = parseInt(-1.7)
console.log(a)